Boiler



JanQS, 1937. o. HARTMANN BOILER Filed Aug. '31, 1935 INVENTOR ATTORNEY Patented Jan. 5, 1937 UNITED STATES I PATENT OFFICE BOILER many Application August 31, 1935, Serial No. 38,680 In Germany September 6, 1934 6 Claims.

This invention relates to a steam boiler of the class in which the steam for use is generated indirectly by means of a heat-delivering device which is placed in the water space of a horizontal or somewhat inclined boiler drum. The invention provides such a heating device consisting of a plurality of closed evaporating drums which are arranged along the length of the horizontal boiler drum and are inclined to the longitudinal axis of such drum, the evaporating drums having evaporating tubes extending through them longitudinally.

The invention offers considerable advantages both as far as the rate of the heat transfer is concerned and as'far as constructional features are concerned. In the case, for example, of a heating element comprising a single closed drum extending substantially over the entire length of the boiler drum, especially when the main boiler drum is comparatively long and of small diameter, there will be only a small pressure dif ference to cause the circulation of the water from the space surrounding the heating drum through the heating tubes as the long heating drums must be placed horizontally, or substantially so. If now such an element is in accordance with the present invention subdivided, it becomes possible to arrange the several portions of the subdivided element in such a way that with the same differential pressure creating the circulation, such circulation will be improved since the resistance of the short tubes is smaller relatively to the differential pressure. As a consequence, a sufiiciently active automatic circulation of the water to be evaporated will occur. The necessity is therefore avoided to use a forced circulation for causing the water to be evaporated to flow through the evaporating tubes as is the case when a relatively long evaporating element is used. Furthermore, the steam liberation is not concentrated at a single point of the boiler drum and the danger of foaming and entraining water is therefore decreased. In addition, the water circulation in the drum becomes more energetic,

. such circulation being around the outside of the Water so that the outer side of the element would also become an effective heating surface. I

From a constructional point of View, the subdividing of the heating element into a number of smaller elements has the advantage that these elements will have a relatively small weight and relatively small dimensions and can therefore be inserted and removed readily, which is an important matter in connection with repairs and cleaning.

The position of the several elements inside of the main boiler drum may be various, as will be noted from the illustrative example shown in the drawing. The elements may, for example, be placed longitudinally of the drum, each having the same inclination, or neighboring elements may be arranged at a certain angle relatively to each other so that the discharge ends of the evaporating tubes of such two elements may be at a common upper point. Also, two or more elements may be arranged side by side transversely of the boiler drum and neighboring elements may be staggered or may be inclined in opposite directions.

The drawing shows by way of example two forms in which the inventive idea may be put into practice.

Fig. 1 shows a vertical longitudinal section of a complete boiler utilizing the invention.

Fig. 2 shows on an enlarged scale and in longitudinal section a portion of the boiler drum with one of the heating elements shown in section and the position of another element indicated in dotted lines.

Fig. 3 is a transverse section on line 3-3 of Fig. 2.

Fig. 4 is a longitudinal section of a boiler drum. showing one arrangement of the evaporating elements.

Fig. 5 is a view similar to that of Fig. 4 showing another arrangement of the evaporating elements.

In the horizontally located boiler drum I there are evaporating elements consisting of a plurality of closed drums 2 arranged longitudinally of the boiler drum and inclined to its longitudinal axis and equipped with evaporating tubes 3 extending longitudinally through them. The closed drums 2 receive the heating medium by means of the connection l3, this heating medium being evaporated in the separate tubular system 5 located in the furnace chamber 4 of the boiler setting; the condensed heating. medium being returned to the evaporating system 5 by means of being so placed that they cross each other and are inclined in opposite directions. Longitudinally of the drum there are two such groups of laterally neighboring elements 2.

The form of the invention shown in Fig. 4 has four elements 2 inclined inthe same direction and arranged end to end in boiler drum I.

Fig. 5 shows an arrangement of the evaporating elements in which alternate ones are inclined in opposite directions. A second row of elements parallel in general to the first one is also indicated, the elements of this second row being inclined oppositely to those of the first row.

As may be seen from Fig's. 2 and 3, the evaporating elements 2 are held in position in the boiler drum by means of a suspending arrange ment 1 which engages the rail 8 by means ofv roll ers so that these small heating elements can readily be put into place or withdrawn. Feed water is carried to the boiler drum I through the pipe 9 by which it is delivered to the cascade plates I0 and to the water space of the boiler drum.. I I is a superh-eater for the steam that has been generated and I2 is an economizer to preheat the feed water on its way to thepipe 9.

What I claim is:

1. In a steam generator in which steam for utilization in a steam using device is generated by means of a fluid heating medium confined in a heating appliance placed within a small-diametered substantially horizontal boiler drum, a heating appliance comprising a plurality of elongated evaporating drumseachhaving tubes extending longitudinally through .itbparallel to its axis, the evaporating drums being arranged in the boiler drum in a row lengthwise of. the boiler drum and each being inclined to the horizontal. 2. Apparatus in accordance with claim 1, the axes of the evaporating drums being parallel to each other.

3. Apparatus in accordance with claim 1, two

successive evaporating drums being oppositely inclined.

4. Apparatus in accordance with claim 1, and further comprising a second row' of evaporating drumsthe drums of which lie abreast of. those of the first row. I v V 5. Apparatus in accordance with claim '1, and further comprising a second row of evaporating drums the drums of which lie abreast of those of the first row and are oppositely inclined to them. j. 6. Apparatus in accordance with claim. 1; successive evaporating drums being oppositely inclined and the apparatus further comprising-a second row of evaporating drums, the drums of the second row lying abreast of those of the first 

